Shakespeare said a rose by any other name would smell as sweet. In fact, many kinds of roses today have little fragrance. But a new discovery might change that.

A study of roses that do have a strong scent revealed a previously unknown chemical process in their petals. Experts said the finding might let scientists restore a pleasing scent to rose varieties that have lost it because of breeding for such traits as color or longevity.

French scientists identified a gene that’s far more active in a heavily scented kind of rose — in a rose called the Papa Meilland — than in a type with little odor. This gene, which produces an enzyme called RhNUDX1, revealed the odor-producing process. The enzyme, which works in the cells of the flower petals, generates the fragrance substance called monoterpene geraniol, the primary constituent of rose oil. Scientists said they think the discovery of the new biochemical pathway can be used to breed pleasant-smelling scents back into modern varieties that lack fragrance.

Results by Jean-Louis Magnard and his colleagues from the University of Lyon in St. Etienne are reported in a study released by the journal Science.